Reducing weight

[Nathan jones]

Drilling brake disks/rotors or lathed for weight, has anybody done it themselves?

Also aluminum fuel tank, maybe to 4 gallon?

I understand if this thread is deleted for lack of substance..

[serialk11r]

Drilling rotors takes a very miniscule amount of mass out of them. Lathing the hats might be substantial but I am guessing cast iron hats are crack prone if they are too thin which is why manufacturers prefer casting them thicker?

I personally would much rather have a larger fuel tank that is heavier. Stopping for fuel is not a good use of time.

Reducing weight to make your car faster makes sense but it doesn't really save a lot of fuel for the effort.

[Nathan jones]

A full tank lasts me 3-4 weeks so going down to 25 litres would still be very efficient timewise and even though E5 is relatively light. Thanks for the reply about the rotors. I also don't have a lathe or pillar drill...

[freebeard]

I may or may not've refilled on the side of the road with the motor idling. Rather than drilling the rotors I cryogenically tempered them to extend the service life.

[oil pan 4]

You want carbon ceramic rotors.

[Nathan jones]

Thanks yes, freezing cast is really backwards for a density reduction technique. Or at worst floating discs with rivets. For now I will skim down 25%, crossdrill then look at ceramics when I have more time 👍

[freebeard]

Are ceramic rotors generally available or is this thread about a specific application?

If it's backwards, you would find something to disagree with here:

https://en.wikipedia.org › wiki › Cryogenic_hardening
Cryogenic hardening - Wikipedia
Cryogenic hardening is a cryogenic treatment process where the material is cooled to approximately −185 °C (−301 °F), usually using liquid nitrogen. It can have a profound effect on the mechanical properties of certain steels, provided their composition and prior heat treatment are such that they retain some austenite at room temperature.

Temper first and the machining should/will have less chatter.

I will have more data soon[-ish]. The car is at the shop and he will pull a rear drum and inspect it, The picture at Permalink #4 is from 2015.

The point with the gas cans is they can run full, empty or without, depending on circumstance. Usually, it's full in the right to balance the driver's weight.

[R.W.Dale]

Selecting the lightest tires and wheels possible would net far more benefits than anything with the brakes.

I have read that removing 1lb of rotational mass is like removing 3 lbs of regular mass in terms of acceleration and I'm sure mpg as well

[Blacktree]

I hate to be rude, but shaving the brake rotors for fuel economy sounds like a boondoggle.

There's a sticky thread at the top of the page, with a list of mods proven to improve fuel economy. That's a great place to start. Best of luck!

[oil pan 4]

I just had rotors turned. New they are about 25mm, they are considered worn out at 24mm.